User stories represent a lightweight approach to use case analysis, a term traditionally used in software engineering to describe a similar process.
在传统的软件工程中，人们使用案例分析。而用户故事（user stories）是一种了轻量级的使用用户案例分析的方式，描述了相似的流程。
A full use case analysis would include the use case name; actor(s); goals of the action; summary of the use case; preconditions (state of the world before the action);
一个完成的使用案例分析，应当包括：案例的名字；参与者（actor）；行为的目的；使用案例总结；前提条件（在这个行为前，世界的状体）；
steps occurring in the scenario (both the actions performed by the user and the system’s responses); related use cases; and postconditions (state of the world after the action). 出现在这个场景中的步骤（包括用户的行为和系统回复的行为）；
相关的用户案例；和后条件（这个行为结束后的世界的状态）；
A use case diagram is a UML-like diagram (see Chapter 10) with stick figures standing in for the actors, and can be used to generalize or extend use cases or to include a use case by reference.
一个 使用案例图表 图表类似UML图表，并用小棍子代表参与者，并且可以通过引用来生成、扩充、包含其他用户案例。
For example, if we have a use case for “user logs in” and another use case for “logged-in user views her account summary”, the latter could include the former by reference, since a precondition to the second use case is that the user has logged in.”
例如，我们有一个“用户登录”的使用案例，并且有另一个叫做“登录后的用户，查看他的账户总结”的使用案例。 后者可以通过引用来包括前者，既然登录是第二个用户案例的一个前置条件。
